CVS Series 470 Piston Actuator – Inspection and Maintenance
Certain operating conditions may require increased inspection and maintenance intervals.
Note: Ensure proper Safety and Lockout procedures are followed prior to inspection.
Relieve all pressure to the actuator and disconnect air supply line to avoid sudden open or
close action of the valve.
Shut off process to the valve or use bypass to isolate and relieve process from both sides of
the valve installation.
1. Verify the control valve is bypassed, pressure is relieved, and proper safety procedures are
followed.
2. Remove the stem connector.
3. Remove the Socket Head Cap Screws connecting the Piston Cylinder to the Piston Cylinder
Flange.
4. Remove the cylinder from the cylinder flange. It may be necessary to use a flathead
screwdriver or similar to pry the connection, once all cap screws have been removed.
5. The Piston and Piston Rod should be able to be removed with the Piston Cylinder when
lifting off of the Cylinder Flange. Once removed the Piston and Rod may be pulled out of
the Piston Cylinders open end. Take caution to not score or damage the cylinder walls.
6. Remove the Upper and Lower Seal Bushings. The Upper Seal Bushing is located at the top
end of the Piston Cylinder, the Lower Seal Bushing is located on the top end of the actuator
yoke.
Once disassembled, inspect all components for excessive wear or damage. Replace worn
O-Rings as required, lubricate with Lubriplate Mag-1 or equivalent.
Reassembly: in order to reassemble the Piston Rod Extension after removal from the Piston
Rod, clean the threads and inspect for visible damage, replace if necessary. Apply Loctite 242
or equivalent thread sealant. The torque value for the Piston rod Extension it 150 ft/lbs .
Reassemble the CVS 471 Actuator in reverse order as described above.
Contact a CVS Controls Ltd. representative for more information or to order spare parts as
required.
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